Abstract
An approach to the in situ testing of mine backfills is outlined. It has been developed to provide a measure of the effective strength and stiffness of such materials after placement in stapes. This paper is based upon recent field studies undertaken at five Quebec mines. Details of the selected instrumentation, supporting equipment and testing procedures are reviewed. The mechanical behaviour of the backfills is reported and related to their physical properties. This approach represents an economical, simple and reliable means to assess the mechanical characteristics of backfill materials as an aid to both mine design and placement quality control.